0x00000021 BSoD: What is it & How to Fix it

Try performing a system restore to take things back to normal

4 min. read

Updated onApril 2, 2024

updated onApril 2, 2024

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Our readers have reported coming across 0x00000021 – QUOTA_UNDERFLOW Blue Screen of Death error. This basically puts their PCs in a restart loop. Windows 10 users are the ones that are affected because of this 0x00000021 BSoD erroramong other BSoD problems.

Why am I getting the 0x00000021 – QUOTA_UNDERFLOW error?

After going through various user reports and forum posts, we have listed down some of the most common reasons that could trigger the 0x00000021 QUOTA_UNDERFLOW BSoD error on your PC:

Let us check out the solutions to resolve the 0x00000021 – QUOTA_UNDERFLOW error.

How can I fix the 0x00000021 – QUOTA_UNDERFLOW BSoD error?

1. Perform a Startup Repair

You may also use a dedicated tool and fix the BSoD or startup problem pretty easily. For that, we have listed thebest boot repair toolsthat you can use on your Windows 10 PC.

2. Fix corrupt system files

You can easily resolve the system file corruption by using the above two commands and hopefully fix the 0x00000021 – QUOTA_UNDERFLOW error.

Besides this, you can try aspecialized repair toolthat can fix broken system files automatically in less than 5 minutes.

3. Update the drivers

4. Scan your PC for viruses

Using the Windows Security tool, you can remove the virus or malware from your PC. However, it isn’t proven to be that effective as compared to dedicated antivirus tools.

We have compiled a list ofsome of the best antivirus softwareto protect your PC from various malware and also resolve issues such as 0x00000021 – QUOTA_UNDERFLOW error.

5. Perform a System Restore

You can perform the system restore in order to take your PC back to a state where everything was working without any issues.

That is it from us in this guide. Windows 11 users are reportedly coming across theBlack Screen error, which you can easily fix by following the solutions mentioned in our guide.

Let us know in the comments, which solution fixed the problem for you.

0x00000021 BSoD: What is it & How to Fix it#

Why am I getting the 0x00000021 – QUOTA_UNDERFLOW error?#

How can I fix the 0x00000021 – QUOTA_UNDERFLOW BSoD error?#

1. Perform a Startup Repair#

2. Fix corrupt system files#

3. Update the drivers#

4. Scan your PC for viruses#

5. Perform a System Restore#